Furnace for the heat treatment of sheets



Patented Dec. 8, 1931 UNITED STATES MILLARD J'. BOYD, or' TORONTO, OHIO, ASSIGNOR TO FoLLANsBEE IoTHERs COMPANY, or PITTSBURGH, PENNSYLVANIA, A 'CORPORATIONIOFPENNSYLVANIA* FURNACE FOR\ THE HEAT TREATMENT oFsHEETs ,a

Application filed June e, as s rialnt. 542 ,53 7

This invention relates broadly to sheet normalizing furnaces, and more specifically to that type of contnuous furnace in which the metal sheets are advanced through the n ormalizing chamber on theperipheries of rotating disks.

The primary object of the invention is to provide, in a furnace embodying sheet-con- Veyor disks, simple and practcal means whereby, during operation, the peripheral carrying surfaces of said disks are constant ly subjected to abrasi on to the extent' that they are maintained in a polished condition, or free from the formation thereon of the usual pin-head projections and surface inequalities which might pit or otherwise mar the surfaces of sheets advanced thereon.

A further object is to provide a furnace of the character mentioned having beneath the conveyor disks a floor or hearth upon which is maintained a loose bed of a 'suitable 'abrasive material having such depth that' the lower portions of the peripheral surfaces of the disks are constantly embedded therein, or at least have wiping contact therewith, for effecting removal therefrom by abrasion of foreign matter or deposits which, if permitted to remain and/ or accumulate, would tend to pit or mark the surfaces of sheets travelng thereover.

In describing the inventionin detail, reference is herein had to the accompanying drawings, in which- Figure 1 is a transverse section of a fur 4 nace,1llustrat1ng my 1nvent1on,and-

Figure 2 is a longitudinal section of the i front end portion of. the same.

- In said drawngs, 1 designates the nor malzng chamber of a 'urnace of'the gen- J ournaled for rotation withinthe furnace i chamber is a plurality of transversely disposed relatively 'spaced shafts 7 having their axes located in a common horizontal plane the rotating action of the disks, gradually -end wall of the abrasive material so advanced,

and having fixed thereon spaced, conveyor disks fl8 adapted to transport forwardly on the peripheral surfaces thereof the 'metal sheets which are to besubject'edto heat treati ,a me11t."'`

}The disks are 'disposed at a 'suitable' ele vaton relative to the level of the floor' or hearth 3, and carriedon said hearth is a'bed 9 of'jan ahrasivematerial having a subtantially uniforn'normal depth eXceeding the 00 height', 'of the. undermost portions of 'said' disks relative to said hearth. :i i Whileotherabrasive materials maybe ein-j ployed'in theformatiorof said`bed9, gravel, or. 'a mixture of gravel'and sand, is at present preferred, the same being intrdiiced within the f rnace (allahu el "by any appropriate meansfas through 'one or more' 'suitably located v openingsor pas'sages' :10' provided *in the rownfl, QA herein shown', a hopper-like recept acle ll is'm'ountedover and m open ommunicationflwith said 'passage and is adapted'to "receive and 'direct downward' to and. through said passage the material' supplied thereto.

The rotating u V disks 8 servetogradua'llyadvance and spread the abrasive 'material de p osited,j as 'aforesaid,` within ;the furnac chamber forming a bed ofjapproximately 1, uniform depth, which depth normall is such thatsaid disks arepartally embe ded in themat'eral; u so embedded, the entire peripheral, or sheet-carrying, surface of each disk is subjected, in each revolution of the latter, to frictional wiping engagement'with the abrasive material of the bed, resulting in maintaining said surface at all times in a smoothly polished condition.

Obviously, the material of the; bed 9 is, by b shifted toward the front end wall 5 of the furnace, thus producing a gradual lowering of the level of the top surface of sadbed.

To prevent the piling up against said front an exit port or passage 12 is provided in said front wall at an appropriate elevation, through which said material may escape outwardly, as indicated in Fig.'2 of the drawings. This escaped material may fromtime i to time be collected and rentroduced in .the furnace for re-use.

What is claimed isl. In a furnace for the heat treatment of 5 metal sheets, the combination With rotating conveyor disks, of a bed of loose gravel having partially embedded therein peripheral portions of said disks.

2. In a furnace for the heat treatment of metal sheets, the combination with rotating eonveyor disks, of a bed of loose abrasive material in which are embedded the undermost perpheral portions of said disks.

3. In a furnace for the heat treatment of metal sheets, the combination with rotating conveyor disks, of a bed of loose abrasve material in which are embedded the undermost peripheral portions of said disks, means in the furnace forintroducing material for the formation of said bed, and a passage for egress of material from said bed following shiftng thereof out of effective range of said dsks. e

4. In a furnace for the heat treatment of sheets, the eombination with a furnace chamber and a succession of conveyor disks arranged over the hearth of said chamber, of a bed of loose abrasive material carried by said hearth, said bed having a substantially uniform normal depth exceeding the elevation of the undermost portions ofthe peripheries of said dsks relative toisaid hearth.

5. In a furnace for the heat treatment of sheets, the combination with a furnace chamber and a successon of conveyor disks arranged over the hearth of said chamber, of a bed of loose abrasive material carried by said hearth, said'bed having a substantially uniform normal depth eXceedn the eleva- 9 tion of the undermost portons o the peripheres of said disks relative to said hearth, said chamber having theren a passage through which material of said bed may escape following shifting thereof past the last of said successon of disks.

In testimony whereof, I afiix my signature.

MILLARD J. BOYD. 

